1. Field of the Invention
The present invention relates to sampling of soil gas and ground water, and more particularly to a soil gas and ground water sampling system and method for rapidly and accurately obtaining such samples.
2. Description of the Prior Art
The testing of ground water in the United States and other areas of the world has become increasingly important in recent years due to discovery of contamination of such waters by industrial and agricultural activities. In the past, it has been necessary to drill monitoring wells to the desired depth to obtain an accurate sample of ground water. This technique has the obvious disadvantages of being extremely time consuming and difficult to properly construct. When monitoring wells are employed for determining the true contaminant levels in aquifers at various depths, foreign materials can be introduced during the retrieval of samples which would alter the true ground water quality obtained by monitoring wells and volatilization of the samples can produce errors. One attempt to improve on this common technique is the BAT sampler developed by BAT Envitech, Inc. of Long Beach, Calif. The BAT sampler utilizes a small evacuated glass vial which is lowered into the monitoring well and filled by punching with a needle. Another approach is a device developed by James M. Montgomery Consultants in Pasadena, Calif., known as the Hydropunch. This device is a sampler that is driven into the ground and allowed to fill from the piezometric pressure of the ground water with no control or monitoring of the filling process. During insertion of the Hydropunch sampler, it is exposed to soil and ground water which overlie the depth at which a sample is to be taken permitting contamination of the sample.
There is a need for a soil gas and ground water sampler and method which will permit rapid sampling at any required depth in soil without drilling of monitoring wells, which has the ability to sample water from existing monitoring wells, open bodies of water, in and around buried tanks, and the like and in which the water sample can be obtained under close control of filling of the sampler, to minimize introduction of foreign contaminants, and to eliminate volatilization of the water sample.